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Thread: Reading new plugs
09-12-2020, 05:36 PM #1
Reading new plugs
So, as some of you know, I’ve graduated from baby boost recently and starting to push 20psi. I used to use the tr-6 with lower boost and went with the br7ef when I started turning it up. The last gap I ran was .030 on the br7’s (measured when I pulled the plug) I can’t really get a good reading on the strap for heat range and the porcelain seems to be towards the 7 o’clock position. Symptoms I’ve noticed is that it’s cutting out a bit at the top of 7k rpm. While I know I’m pushing limits of factory coils, I’m wondering if I should continue to run this plug with maybe a tighter gap?
09-12-2020, 06:31 PM #2
The ground strap seems to show it’s in the correct heat range, yes it’s a bit fat on the mixture, maybe just close up gap to .027 and see if she cleans up.
09-12-2020, 11:44 PM #3
I can't remember what fuel you are running, Matt but the plug looks like it is ethanol or methanol. What is your commanded AFR or lambda and what is your measured AFR at the O2 sensor?
09-13-2020, 02:34 AM #4
09-13-2020, 03:04 AM #5
Under load I’m seeing 10.8-11.2 on a Bosch sensor that’s a few days old.
09-13-2020, 12:27 PM #6
I have always ran my gap at .018.
09-13-2020, 02:17 PM #7
I was riding in a friends Hellcat the other day and he was showing me all the nice stuff in their instrumentation package. One was an AFR meter. Driving around in traffic basically n/a the car would show high 12's to mid 13's for the AFR. The moment he put his foot in it the AFR instantly dropped to 10.8 and crept back to an 11.2 AFR after a second or so. Dodge does this for both warranty and performance reasons. The sudden hit drops it to the 10.8 threshold is attributable to increases in transient fueling, essentially simulating an accelerator pump shot. The 11.2 WOT AFR is a "safe" target for warranty purposes.
I am sure there is more power with a slightly leaner WOT target AFR but if I am also paying for the engine repairs I would step back from the brink slightly (like Chrysler did) and let discretion be the better part of valor with an 11.2 or thereabouts AFR. If I was running an E-10 91/93 octane fuel them I would probably go a tenth or two richer just for safety.
Your ignition is going to be a limiting factor on upper rpm performance. The easiest initial fix is decreasing the gap to around 0.020" or slightly less like y2kgt suggested. My memory is telling me you upgraded to an aftermarket ECU. If that is correct then give some consideration to upgrading the OEM COPs to the IGN1 or IGN1-A coils for a huge increase in spark energy. FWIW the 'dumb' IGN1 coil is actually a whisker stonier than its smart ING1-A cousin.
Parting thought, remember small plug gaps foul easier than larger plug gaps. Use the highest energy ignition you can afford and the largest reasonable gap that still gets the job done for a street brawler.
09-13-2020, 04:11 PM #8
Stock pcm still, I do favor the “safer” a/f ratio. Like I said, ignition is lacking for sure, I saw the ign-1 coils putting out slightly more voltage but I haven’t personally seen/heard anyone running them. The most I’ve seen is the kenne bell spark booster. Are the ign-1 coils worth the upgrade?
09-13-2020, 05:11 PM #9
Modmotors have stunning power potential above 7000 rpm but OEM electronics artificially limit them to the sub 7000 rpm world or if you can shut off enough code and you can get above 7000 rpm the ECU has no reserve available. The OEM Cobra ECU uses a software configurable clock switch that can be set as high as 25 Mhz up from 10 or 15 Mhz but the Intel CPU that is used is pretty much out of steam even at 25 Mhz with all the EPA work that Ford needed to ask it to do. This is work we never require for a race car application. Some of the code can be turned off some can not. The upshot is that it is a good street ECU and also a necessary ECU if you want to pass emissions but a poor choice for a race application.
The easiest (and one of the best) fixes is the MS3Pro Plug-n-Play ECU they make for the 03/04 Cobra's. This is about as easy a fix as there is. You unplug the OEM ECU, plug in the MS3Pro ECU, load the supplied starter tune and start the car. It uses the same power feeds, wiring harness etc as the OEM Ford unit but gives you performance out to 10 or 12,000 rpm, I forgot which. It also has direct support for the IGN-1 coils, multiple engine fail safes, traction control, knock detection and prevention along with a list of additional features that is too long to list here. BTW it also comes with tuning and dataloging s/w and has support for wireless tuning and dataloging eliminating the cumbersome cable that is typically required. For the worrywart types, the laptop to ECU communication uses a protocol with built in data corruption detection and correction. Additionally, you don't have to buy proprietary repackaged OEM sensors at inflated prices, the ECU uses all the original Ford sensors. At about the price of a set of pistons ($1,349) this ECU should be a no brainer.
BTW, although not really a race specific feature, the other nice touch that the MS3Pro ECU brings is support for the entire Mustang gauge cluster so the dash looks and operates the same as the original vehicle. Almost forgot. You know all those fancy digital dashes from RacePack and others. Well the MS3Pro code supports android tablets so you can build a dash with any of their many, many predawn gauges on the android and have it display engine operating metrics wherever in the car you want to place it. Pretty cool, and there is so much more ...
Check it out here => MS3Pro PnP for Cobra and while you are on that page check out the 6 minute or so install video and the excellent first start video that follows it.
p.s. I forgot to mention that their ECU has a wealth of turbo specific features that are software selectable in the code which you can turn on and off with mouse clicks and tune to your particular car and driving style.
Last edited by eschaider; 09-21-2020 at 04:51 PM. Reason: Added Postscript
09-13-2020, 05:54 PM #10
Is the factory pcm capable of running either of those coils? Just interesting that there is very little plug and play coils, even the msd’s don’t offer spectacular gains in fire. It “seems” simple, using the factory input to fire the plug, and have a winding coil to increase voltage. I believe this is how the kenne bell works.
09-13-2020, 05:55 PM #11
As for a quick fix for this weekends excursions, I closed up the gap to .020.
09-13-2020, 09:25 PM #12
The KB Boost-a-Spark does not change the windings in the ignition coils, It merely supply a higher voltage to the coil just like a Boost-a-Pump does for a fuel pump. even when you bump the voltage from 14 volts to 16 or 17 volts you are getting a very small (17% to 20%) increase in voltage at the plug. Voltage just provides the push to jump the spark gap it does not provide the heat to light the fire. The heat to light the fire comes from the mj of energy the coil can provide.
An OEM COP is in the 15 mj (typical) to 18 mj (best case) energy space. The IGN-1 coils are in the 118 mj space or about 700% more energy at the plug tip than an OEM COP. When the IGN coils fire it is like lightening bolt strikes under your hood. These are the preferred coils for blown alcohol ProMods for that very reason. They are the only alternative to 44 amp MSD Mags for supercharged engines.
Last edited by eschaider; 09-18-2020 at 11:56 PM. Reason: Spelling and Grammar
09-21-2020, 03:35 PM #13
I know you're in the process of ditching the 2V coils but since you just ohm'd yours at .7 and good is "supposedly" 1.8+ I wonder if your coils were simply getting weak?
I can't wait to see how the better ones work for ya!